1. Field of the Invention
The present invention relates to a new method for producing optically active oxodicyclopentadiene which is an intermediate of pharmaceutical products and the like.
2. Description of the Prior Art
The optically active oxocyclopentadiene is very useful for starting materials of physiologically active materials such as pharmaceutical products. For example, it is known that the compound is a starting material of Aphanorphine having analgesic effect (J. Chem. Soc. Chem. Commun., 290 (1990)).
However, a well-known methods for producing the optically active oxocyclopentadiene uses optical resolution (J. Chem. Soc. Chem. Commun., 271 (1989), Synlett., 636 (1991), and Synthesis, 1237 (1995)), so that one of the enantiomers becomes useless. Accordingly, to use the one, it should be reacted via several steps to obtain the antipode.